SPECTROSCOPIC PHOTOACOUSTIC IMAGING FOR MOLECULAR AND FUNCTIONAL IMAGING OF CANCER DIAGNOSIS
***** Seminar *****
Center for Integrated Bio and Nano Systems
Houston Chapter of IEEE Nanotechnology Council and Houston Chapter of IEEE Magnetics Society
Friday, Dec. 6, 2013
12:30 p.m. (Refreshments served at noon)
Room: W122 Building D3
Spectroscopic Photoacoustic Imaging for Molecular and Functional Imaging of Cancer Diagnosis
Department of Cancer System Imaging
UT MD Anderson Cancer Center
Photoacoustic imaging (PAI), also referred to as optoacoustic imaging, is based on the measurement of ultrasonic waves induced by biological tissues’ absorption of short laser pulses. PAI employs nonionizing laser light to acoustically visualize biological tissues with high optical contrast and high ultrasonic resolution. Acquiring images at distinct laser wavelengths makes spectroscopic photoacoustic imaging (SPAI). Spectrum analysis enables spectroscopic separation of signal contributions from multiple optical absorbers (e.g., nanoparticles as molecular marker, oxyhemoglobin, and deoxyhemoglobin) and then reveals molecular and functional imaging. In addition, SPAT may be developed to imaging gene expression by imaging a report gene or to monitoring of delivery of vectors to specific cells in gene therapy. However, there are some technical challenges that must be overcome for this new imaging modality going to reality although the concepts have been demonstrated.
PAI brings a breakthrough in imaging depth of optical imaging because defused light also induces photoacoustic signals. While the optical penetration is maximized with near-infrared laser as excitation radiation, the optical contrast is enhanced by nanoparticles whose absorption peak matched the laser wavelength. Our PAI clearly visualized nanoparticles in mouse brain and rat lymph nodes to reveal tumorgenesis. Moreover, Agarose gel containing nanoparticles embedded in chicken breast at the depth of ~ 5 cm could be readily imaged with an in-plane imaging resolution of ~ 800 µm and a sensitivity of ~ 0.7 nmol per imaging voxel. Our study indicates that it should be possible to image lesions in the human breast at a depth of up to 40 mm with imaging resolution and sensitivity similar to that obtained with nanoparticles in chicken breast muscles.
Bio of Dr. Ku:
Dr. Geng Ku is an assistant professor in Department of Cancer System Imaging at UT MD Anderson Cancer Center. Before joining MD Anderson, he was a research assistant professor in Department of Biomedical Engineering at Washington University in St. Louis. He received his Ph.D in Biomedical Engineering from Texas A&M University, his MS and BE degrees in Optoelectronics from Huazhong University of Science and Technology. He has been working on photoacoustic imaging (laser) and thermoacoustic imaging (microwave) since 1999.
Contact Prof. Jiming Bao (jbao [at] uh [dot] edu) if you would like to arrange for a time to meet with Prof. Ku.